Brake block



R. J. STOKES BRAKE BLOCK AFiled July '7, 1921 a@ shaped and vulcanizedPatent-edi .liuiy 17, 1923.

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ROBERT J. s'roKEs, or 'raENro1\T,

NEW JERSEY, ASSIGNOR T THERMOID RUBBER GOM- PANYfOFEAMILTON TOWNSHIP,NEW JERSEY, A CORPORATION OF NEW JERSEY.

BRAKE BLOCK.

Application led July 7, 1921.

To all whom t may concern.'

Be it known that I. ROBERT J. STORES, a citizen of the United States,residing in Trenton, Mercer County, New Jersey, have d invented certainImprovements in Brake Blocks, of which the f llowing is a specification.

One object `of my invention is to make a brake block of a composition ofasbestos l@ iibre, short sections of wire and a binder capable of beingvulcanized so that the brake block, when moulded under heavy pressure,hape to can be made to assume a s correspond with the shape of the drumwith w which it is to come into frictional contact. A further object ofthe invention is to make a brake block so that the ends of the layers ofthe fabric of which it is made will be presented at the wearing surfaceof the. 3@ block. Y In the accompanying drawings: Fig. 1 is aperspectlve view of my 1mproved brake block;

Fig. 2 is atransverse sectional view on the line 2 2, Fig. 3;

Fig. 3 is a sectional View on the line 3-3, Fig. V2;

Fig. blocks 4 is a perspective view of the two of fabric prior to ieingassembled, an

Fig. 5 is a sectional view of the two blocks shown in Fig. 4,-securedtogether prior to being vulcanized.

land 2 are blocks made up of a series of layers 3 of asbestos fabricwoven in strips with a given amount of short sections of fine metallicwire and impregnated, or

. coated, with rubber, or other` material capable of being vulcanized.rlhe block 1 is 6@ out at 4 to form grooves, which are V- shaped, in thepresent instance, so as to resemble, somewhat, the finished grooves inthe block, but it will be understood that the shape of the grooves willdepend materially upon the shape of the ribs of the brake drum withwhich the block engages.

The two blocks 1 and 2 are Secured ltogether by Va vulcanizable cement,as shown in Fig. 4, and then the combined block, Fig.

50 4, is placed in a suitable mold under heavy hydraulic pressure andvulcanized, 4after which the block is removed and will be curved tocorrespond to the curve of the canizing t 'serial No. 482,991.

brake drum, as indicatedv in Fig. 1, and will have the grooves 4*lformed therein of tbe particular shape shown in, Fig. 2, which willcorrespond with the V-shaped ribs of the drum. Each groove has anextension 4* for clearance, and the ribs between the grooves are fiat,as at 5, so as to provide clearance between the face of the block andthe bottom of the space between the ribs of the drum.

`It will be noticed that the block 2 is slightly larger in size than theblock 1 so that when the combined blo'ck, Fig. 4, is placed underpressure and molded it will produce a block of greater width at the backthan at the front, as clearly shown in Figs. 1 and 3.

By the above method, a very substantial brake block can be made, whichcan be molded accurately to the curve of the drum against which it is toact and in which the edges of the woven fabric will be exposed at thewalls of the grooves so that when the block is applied to the drum theedges of the fabric will bear ragainst the ribs of the drum and williirmly hold the drum. By designing the block so that the ends of theibres'are at 'the wearing surface, the life of the block is materiallylengthened.

1. v A curved bearing block having a series of tapered grooves therein,said block consisting of sheets of asbestos fabric and a vulcanizableadhesive, the fabric being discontinued at the grooves.

2. A .curved bearing block consisting of layers of asbestos fabric and avulcanizable binder, the face of the block having tapered, parallelgrooves, the fabric, at and near the face'of the block, being cut toexpose the endsfthereof at the grooves.

3. The rocess hereinbefore described of making a rake block, saidprocess consisting in assembling sheets. of' asbestos fabric that havebeen treated with a vulcanizable adhesive, cutting a series of parallelgrooves in one face -or the block formed by the fabric so as to exposethe edges of the layers of fabric at the grooves, then subjecting theblock to heavy pressure to mold the block into a curved shape, and, atthe same time, vulhe block. f

ROBERT J. STOKES.

